1. Technical Field of the Invention
The present invention relates generally to assembly techniques, and, more particularly, to systems and methods of integrating an assembly tool into a detailed part.
2. Description of Related Art
Aircraft components are generally unique geometric structures whose design is directly related to the size, payload requirements and purposes of particular aircraft which employ them. Consistent with this uniqueness, the manufacturer of a given aircraft design requires the creation of unique and dedicated tooling typically in the form of assembly jigs and fixtures. Further, such unique tooling and production facilities must be maintained and retain ed over the product ion life span of the aircraft and beyond in anticipation of replacement parts. An aircraft manufacturer that makes a fleet of aircraft must provide and maintain separate tooling and facilities for each different aircraft component (such as the wing, fuselage and tail section). The investment for new tooling and facilities for each new aircraft design commonly exceeds many millions of dollars. For this reason, when a manufacturer is considering a new design or a variation on an existing design, the decision to make the new design or variation is greatly influenced by the sizeable amount of the initial investment required to build new tooling and facilities.
In addition to initial investment, other economic factors associated with current aircraft manufacturing techniques also influence direct labor cost and quality considerations. These economic factors include the degree of automation and accessories used in connection with basic tooling. All of these represent ongoing costs to the manufacturer, which are added over and above the initial investment cost for producing tooling and facilities for any component production.
Assembling and fastening together elements of aircraft components is a multi-step process. For example, the elements of a wing assembly may include an aluminum web, a couple of ankle caps and several stiffeners. Once these elements or details are designed the problem lies in the high man hours requirements needed to prepare and position the elements for assembly and further operations such as automatic fastening, for example, as found in modern aircraft assembly plants. Such a preparation process may also include manual drilling and installation of many temporary fasteners to hold the wing assembly in position, as guided by a jig for that purpose.
Traditional practice was for design to focus on performance requirements with little consideration of how assembly could be accomplished in production. Production depended on tool determinate assembly methods, as above-described, to locate parts in xe2x80x9caircraftxe2x80x9d coordinates and make adjustments by shimming or filing at contact areas. These methods lead to work in process laden, station-by-station assembly flow. Reduced tooling assembly methods would support an assembly line perspective by allowing product to flow smoothly through production.
Current emphasis on Lean Manufacturing has initiated the need to develop new methods for streamlining assembly. An innovation of the present invention is the use of part features to locate parts during assembly. Reduced tooling assembly strives to define lean assembly methods which benefit from advances in technology and manufacturing capability by pairing features to achieve assembly location objectives. Projected benefits include reduced assembly tooling and less assembly time.
The above-mentioned and other disadvantages of the prior art are overcome by the present invention, by providing a method and system of integrating an assembly tool into a detailed part and of assembling the detailed parts using self-locating part features.
The present invention achieves technical advantages as a system and method for orienting or assembling a detailed part in a predetermined orientation in which the detailed part is made up of a plurality of component parts. The method first defines a location and alignment of the component parts. Self-locating features, such as locating tabs, integral flanges, locating notches and locating bosses, are subsequently disposed on the individual component parts corresponding to the defined location and alignment. By disposing a unique combination of self-locating features on component parts of the detailed part, a virtual assembly tool is incorporated into the detailed part. In practice, component parts are engaged with predetermined corresponding component parts using the disposed self-locating feature on each part. Thus, proper location and alignment of each respective part is assured, within a predetermined dimensional tolerance. The act of engaging individual component parts is repeated until each of the component parts is fully located and aligned, using the self-locating features, in the predetermined orientation.
Among the new advantageous of the present invention are: First, integration of self-locating features into detailed part reduces or eliminates the assembly and locating tool counts used to assemble components such as Wing Carry Through components; Second, the integration of self-locating features into the detail parts reduce the assembly span time; Third, reduction or elimination of maintenance requirements of locating and alignment assembly tools and, since tools and time are reduced, consequently, the total cost to assemble the detailed part is reduced.